1. Field of the Invention
The present invention relates to an inflatable pillow configured to facilitate the alignment of the oropharyngeal, laryngeal, and tracheal axes of the airway of an individual in the supine position prior to induction of anesthesia and placement of an endotracheal tube. The present invention also relates to a modification of the inflatable pillow to provide left lateral tilt of the uterus as well as facilitating endotracheal intubation in pregnant patients undergoing a Cesarean section.
2. Background of the Related Art
Obesity is an epidemic in the United States and is a leading cause of morbidity and premature mortality. It is estimated that 300,000 deaths a year are related to obesity and close to $100 billion are spent on obesity-related health care costs. Obesity is a chronic condition associated with several comorbid disorders such as hypertension, diabetes, heart disease, and sleep apnea. In the United States, the prevalence has been increasing over the past several decades and in recent published US data (1999 to 2000), 67% of men and 62% of women are overweight. Further, 28% of men and 34% of women are considered obese with 5-7% in the morbidly obese category. The overweight population represents a large segment of the surgical caseload and presents significant challenges to the anesthesiologist, particularly during endotracheal intubation.
One of the most important tasks of an anesthesiologist is the management of the patient's airway during the administration of anesthesia. In order to maximize visualization of the larynx during endotracheal intubation, the anesthesiologist must place the patient's head and upper back in the “sniffing” position to properly align the oropharyngeal, laryngeal, and tracheal axes. The obese patient presents a challenge for proper alignment because of excess tissue in the upper back, neck, and oral pharynx.
Physiological changes occurring during pregnancy further complicate airway management in the pregnant patient. Fluid retention, weight gain, enlarged breasts, incompetent lower esophageal-gastric sphincter and friable mucosal tissue all add to the difficulty of visualization of the larynx during endotracheal intubation. Accordingly, failed intubation during anesthetic induction occurs almost ten times more frequently in pregnant patients than in non-pregnant surgical patients.
Endotracheal intubation is a medical procedure in which an endotracheal tube is inserted through the oral cavity into the trachea to provide controlled or spontaneous ventilation and to protect the lungs from gastric acid contamination. This protection is provided by a balloon on the tip of the tube that is inflated when the tube is in the proper location above the carina. Prior to the induction of anesthesia, a pillow or pad is placed under the patient's head to elevate the head above the shoulders in the “sniffing” position. This “sniffing” position helps align the oropharyngeal, laryngeal, and tracheal axes and facilitates the placement of the endotracheal tube into the trachea. After anesthetic induction, the anesthesiologist or nurse anesthetist places a laryngoscope blade into the mouth, the tongue and jaw are slightly elevated, the trachea and vocal cords are visualized and the endotracheal tube is introduced through the mouth into the trachea. The laryngoscope blade is then removed, the tube balloon is inflated, and proper ventilation of the lungs is confirmed. This procedure is typically carried out in the operating room. However, it is also performed in emergency situations outside of the operating room such as the emergency room, hospital room, or at the scene of accidents.
When the obese patient is supine on the operating table, a standard pillow or pad does not elevate the neck and head adequately above the shoulders to provide the necessary “sniffing” position. As a result, a known current regimen involves placing several layers of blankets under the upper back, neck, and head of the patient to create a ramp in order to elevate an obese patient's upper body so that the pinna of the ear and the sternum are in the same horizontal plane. This may require ten to fifteen blankets in the morbidly obese patient. Although this method of support is efficacious, there are several disadvantages. First, health care professionals are put at risk for injuries as a result of lifting the obese patient for pre-induction blanket positioning as well as lifting the patient to remove the blankets after intubation. Blankets must also be removed so that the patient's shoulders and arms are level with each other in order to minimize the risk of a brachial plexus stretch injury. In addition, the endotracheal tube may become dislodged while lifting the patient to remove the blankets. Further, the cost of laundering the large number of blankets used in each case is significant. Moreover, it is difficult and time-consuming to adjust the blanket placement for proper positioning after the patient is on the operating room table.
The pregnant patient undergoing a Cesarean section, or other surgical procedure, presents two major concerns to the anesthesiologist. In addition to the physiological changes that occur during pregnancy that increase the risk of a difficult intubation, the enlarged, gravid uterus can partially obstruct the venous return to the heart by compressing the inferior vena cava if the patient is left in the supine position on the operating room table. This syndrome can cause a 25-30% decrease in cardiac output resulting in maternal hypotension and decreased blood flow to the fetus. In order to alleviate the decrease in venous return, the right side of the pregnant patient is tilted up 15-30 degrees to the left side of the patient to move the uterus away from the inferior vena cava. Presently, this “left lateral tilt” is obtained by either placing a liter saline bag under the right side or manually inflating a bladder bag under the patient's right side. The former method is non-adjustable and does not allow adequate tilt in large patients. The latter method is burdensome and time-consuming during the critical part of pre-induction preparation and oxygenation.
Accordingly, there is a need for an improved device that allows for specific adjustments in the position of a patient's upper back, neck and head to obtain the best alignment of the oropharyngeal, laryngeal, and tracheal axes in obese and pregnant patients so that endotracheal intubation can be performed quickly with minimal trauma to patients. There also exists a need for a device that prevents injury to health care professionals performing endotracheal intubation by eliminating the need to lift obese patients before and after induction of anesthesia. There is a further need for a device that allows anesthesiologists to quickly and adequately obtain a left lateral tilt in pregnant patients irrespective of the patient's anatomy.